The number of combustion engines in use today is in excess of hundreds of millions of engines. These combustion engines typically operate through the ignition and combustion of fuels such as fossil fuels. Many of the vehicles use gasoline and/or diesel fuel.
Diesel, gasoline and other relevant fuels, however, typically are not fully consumed or burned upon ignition of the fuel. As a result, some of the fuel, and often a significant percentage of the fuel is wasted and expelled as exhaust. This results in large amounts of emissions and lower fuel efficiency.
The accumulated effect of the large amounts of emissions from the millions of combustion engines accounts for a significant portion of today's air pollution. Further, because of the lower efficiency, the cost for operating these engines can be high and in some instances inhibitively high. Still further, the lower efficiency results in greater fuel consumption which can lead to a dependence on sources of fuel.